Sounds like you're taking a big picture plan and getting through it one bite at a time...I've done a number of projects in a similar fashion, where there is a "big picture" plan, but for now we have the resources for step 3 and 5...some time later, 1 and 4 get done, then 2. As long as there is a certain amount of flexibility in the plan to account for changing project specs, found materials, cool things stumbled upon along the way, and the odd piece of immovable ledge right in the middle, you usually end up coming out pretty good along the way.